Highlights
- Antiviral medications help limit the severity of infection and the spread of influenza viruses.
- Currently, there are four antiviral medications approved by the FDA for treating influenza, each with different side effects and mechanisms.
- BidRx can help you get the anti-influenza medication you need at the best price.
According to the CDC, between 2010 and 2020 alone, the influenza virus was responsible for up to 41 million illnesses, 710,000 hospitalizations, and 52,000 deaths annually. While the severity and risk of the flu has dropped substantially compared to early pandemics, prevention and treatment is still the best cure. In this article we’ll discuss what anti-influenza drugs do, who should take them, and when to use over-the-counter medication.
Influenza Medications and What They Do
There are four FDA-approved anti-influenza antiviral medications as of this writing:
- Oseltamivir phosphate (Tamiflu)
- Zanamivir (Relenza)
- Peramivir (Rapivab)
- Baloxavir marboxil (Xofluza)
All have the same basic mechanism, interfering with how the influenza virus replicates and keeping it from spreading. Some are recommended for different flu strains, although study is ongoing.
Antivirals do not kill a virus directly. Instead, they block viral reproduction, giving the immune system time to track down the virus and wipe it out. This also helps people sick with the flu from spreading it too widely, although this shouldn’t be relied on to keep a household safe. Because flu vaccines can interfere with antiviral effectiveness, you should wait at least two weeks after getting a vaccine before taking any antiviral medication.
Oseltamivir Phosphate
Also called Tamiflu, oseltamivir phosphate is currently the only antiviral for the flu available in generic form. It’s currently used to treat the A and B strains of the flu.
Mechanism of Action — Oseltamivir Phosphate
Oseltamivir phosphate inhibits the enzyme neuraminidase, which the flu virus excretes to open the cell wall and allow new flu particles to escape. Blocking neuraminidase effectively traps the virus in the cell.
Indications — Oseltamivir Phosphate
Oseltamivir isn’t recommended for typical flu infections due to concerns of flu strains developing resistance. People at high risk of serious infection who have shown symptoms for less than two days are the best candidates for oseltamivir.
Contraindications — Oseltamivir Phosphate
Speak with your doctor if you have any of the following:
- Kidney disease or kidney impairment
- Heart disease
- Chronic lung disease
- Risk of brain swelling or disorder
- Immune system concerns
Side Effects — Oseltamivir Phosphate
The most common side effects of oseltamivir are nausea and vomiting.
Zanamivir
Zanamivir also acts on influenza A and B. Zanamivir is only available as an inhaled medication.
Mechanism of Action — Zanamivir
Zanamivir blocks neuraminidase by binding to the proteins it acts on. This traps flu particles inside cells, making them easier to target.
Indications — Zanamivir
Zanamivir is recommended for people at high risk who have no respiratory complications that might make an inhaled medication dangerous. It isn’t recommended for otherwise healthy people.
Contraindications — Zanamivir
If you have a chronic respiratory illness like asthma or COPD, zanamivir is not recommended. It also should not be taken by anyone with a lactose or milk sugar allergy due to ingredients used in its formulation.
Side Effects — Zanamivir
There have been few meaningful reports of adverse side effects with zanamivir. However, if a person taking it is showing sudden or unusual changes in mood or behavior, take them to a doctor immediately. Both the flu and interaction with zanamivir have a small risk of psychiatric side effects best treated at a hospital.
Peramivir
Peramivir is only available intravenously and is generally used to treat influenza A and B. It is a single-dose medication, generally given by a healthcare professional. As it’s relatively new, it’s most effective against strains that may have developed resistance to oseltamivir and zanamivir.
Mechanism of Action — Peramivir
Peramivir binds to neuraminidase directly, preventing it from acting and keeping the flu virus contained.
Indications — Peramivir
Anyone at high risk of influenza and showing signs of illness can receive peramivir within 48 hours of showing symptoms.
Contraindications — Peramivir
If you have kidney disease, talk to your doctor before accepting peramivir. You shouldn’t take Peramivir if you’ve had a flu shot in the last two weeks.
Side Effects — Peramivir
The most common side effect of peramivir is gastrointestinal, usually diarrhea or constipation. Some patients also report insomnia.
Baloxavir Marboxil
Also targeting the A and B strains, baloxavir marboxil is a single-dose medication taken orally.
Mechanism of Action — Baloxavir Marboxil
Baloxavir targets endonuclease, which allows the flu virus to “snatch” short chains of RNA from the cell it needs to reproduce.
Indications — Baloxavir Marboxil
Because it’s unusually vulnerable to resistance, baloxavir is generally used for acute cases of the flu with no complications. It can also be used as a preventative measure post-exposure for people at risk who’ve been exposed to the flu.
Contraindications — Baloxavir Marboxil
There are few contraindications for baloxavir. However, the medication is based on the patient’s weight, so it should not be shared.
Side Effects — Baloxavir Marboxil
Common baloxavir side effects include:
- Cough
- Chest congestion
- Nausea
- Diarrhea
- Headache
- Runny or stuffy nose
When Should I Use Over-the-Counter Medication or Home Remedies?
If you’re otherwise healthy and have no complications, your doctor will likely recommend resting and drinking fluids while the disease runs its course over the course of five to seven days. Even with an antiviral, you can expect at least some symptoms and a need to stay home for a while.
Over-the-counter medications will help manage symptoms, although they won’t prevent the spread of the flu. Similarly, home remedies such as hot showers, tea and honey, and chicken soup are most useful for mitigating symptoms and staying hydrated.
Be Ready for Flu Season With BidRX
If flu season is particularly risky for you, the best way to deal with it is to be prepared. Because antivirals are most effective taken within 48 hours of exposure or symptoms, talk to your doctor about keeping flu medication on hand. If they agree, find the lowest price for flu medication through BidRX.
Simply create a bid for the medication you need, and pharmacies across the country will submit their best price to ship to your door, or for you to pick up locally. Particularly if you’re working to limit exposure, you can get your preparations in order with minimal risk.
To get started, visit our antivirals page. Once you see how BidRX can save you money, it’ll be your first stop for every prescription.
